Abrasion resistant energy absorbing treadmill walking/running belt

ABSTRACT

An endless belt ( 10 ) for use in exercising treadmills is provided. The endless belt includes at least an underlying ply ( 18 ) of low friction material, an internal core ( 38 ) of compressive and resilient material, and an overlying skin ( 42 ) of abrasion resistant material. The internal core ( 38 ) consists of a series of transverse projections ( 30 ) having inclined side walls ( 46, 47 ). The shape of projections ( 30 ) of the internal core ( 38 ) allows for the compression thereof while providing a suitable walking/running surface. The underlying ply ( 18 ) minimizes friction between the belt and any underlying support. The overlying skin ( 12 ) increases the durability of the belt while providing friction between a user&#39;s foot and the belt ( 10 ) for movement thereof. The belt may further include a reinforcing ply ( 32 ) disposed between the underlying ply ( 18 ) and the internal core ( 38 ).

TECHNICAL FIELD

This invention pertains to the art of endless belts for use inexercising treadmdills, and more specifically to a belt construction foruse in an exercising treadmill.

DISCLOSURE OF INVENTION

In the art it is known to use endless conveyor-type belts on exercisingtreadmills to simulate a walking or running exercise. While conveyorbelts useful in industry often employ supporting rollers along theirlength, such arrangements are unsatisfactory for exercising treadmillsbecause of the bumpy sensation caused thereby. Merely eliminating thesupporting rollers, however, causes friction problems between theunderside of the belt and the supporting surface.

The conveyor belt system disclosed in U.S. Pat. No. 3,711,090 to Fielderattempts to overcome the friction problem by providing a belt having alow-friction sheet on an inner portion of the belt which moves against aflat support surface which is similarly lined with low-frictionmaterial. The support system provides a rigid base without providing forany vertical movement of the belt, or cushion, when in operation.

In order to reduce the likelihood of injury to a user of an exercisetreadmill, it is beneficial to provide a yieldable surface whichcushions the vertical movements of the user.

U.S. Pat. No. 3,689,066 discloses a fairly complex system whereby aseries of collapsible bellows undergird an upper belt section in aneffort to provide resilient and yieldable support thereto. The series ofbellows are located beneath the inner belt surface and are overlaid witha low-friction sheet. The belt slides against this low-friction sheetduring operation of the treadmill.

European Patent Document EP 196 877 discloses a shock absorbent movingplatform for use in exercising.

The present invention provides a yieldable and resilient belt for use inan exercising treadmill which further provides a low-friction surfacefor effective movement of the belt.

According to one aspect of the invention, an endless belt for use withan exercising treadmill comprises a planar first portion comprising acontinuous underlying ply of low friction material, and a second portioncomprising a series of projections. Each projection has a pair ofoppositely inclined side walls and a top, the top being generallyparallel to the plane of the first portion. The projections extend thewidth of the belt and the tops are laterally spaced transverse to thelengthwise dimension of the belt.

According to another aspect of the invention, each of the projectionscomprise an internal core of compressible and resilient material, and anoverlying skin of abrasion resistant material.

According to another aspect of the invention, the low-friction materialis selected from the group consisting of: ultra high molecular weightpolyethylene (UHMW-PE), nylon, polyester, etc.

According to another aspect of the invention, the compressible andresilient material is selected from the group consisting of:polynorbornene, foam, butyl.

According to another aspect of the invention, the overlying skin isselected from the group consisting of: abrasion resistant synthetic,natural rubber or blends thereof.

According to another aspect of the invention, the first portion furthercomprises a reinforcing ply disposed between the underlying ply and thesecond portion.

According to another aspect of the invention, an endless belt for use inan exercising treadmill comprises a continuous underlying ply of lowfriction material, an internal core of compressible and resilientmaterial, and an overlying skin of abrasion resistent material attachedto the internal core. The internal core has an inner surface coextensivewith the underlying ply, and an outer surface having a plurality oftransversely extending V-shaped grooves therein.

One advantage of the present invention is the provision of an energyabsorbing internal core in the construction of a belt for use with anexercising treadmill.

Another advantage of the present invention is the provision of anunderlying ply of low friction material in the belt construction to aidmovement of the belt against a supporting surface.

Another advantage of the present invention is the cross-sectional shapeof the upper portion which allows for expansion of the internal coreupon compression of an upper belt section.

Another advantage of the present invention is the provision of V-shapedgrooves in the outer surface which helps the belt ease around endrollers.

Still other benefits and advantages of the invention will becomeapparent to those skilled in the art to which it pertains upon a readingand understanding of the following detailed specification.

BRIEF DESCRIPTION OF DRAWINGS

The invention may take physical form in certain parts and arrangement ofparts, a preferred embodiment of which will be described in detail inthis specification and illustrated in the accompanying drawings whichform a part hereof and wherein:

FIG. 1 is a schematic, side view of a part of an endless belt for use ina exercise treadmill according to the present invention.

FIG. 2 is a side, cross-sectional view of the endless belt showing afirst, uncompressed configuration.

FIG. 3 is a side cross-sectional view of the endless belt showing asecond, compressed configuration.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings wherein the showings are for purposes ofillustrating a preferred embodiment of the invention only and not forpurposes of limiting the same, FIG. 1 shows part of an endless belt 10of the type used in exercising treadmills, including upper belt section12. The belt construction of the present invention will be discussedwith respect to the upper belt section 12, although is should beunderstood that the belt construction so disclosed extends throughoutthe length of the belt 10.

In a preferred embodiment of the invention, the belt 10 comprises twodistinct portions. The first portion 14 is innermost and is generallyplanar along upper belt section 12. The first portion 14 comprises atleast a first underlying ply 18 of low-friction material, such ascotton, polyester, and nylon. A preferred embodiment of the presentinvention utilizes UHMW-PE or polyester as the material of the firstunderlying ply 18. The first underlying ply 18 has a innermost surface20 which slidably engages a supporting structure 22 disposed beneath theupper belt section 12.

The second portion 28 of belt 10 is outermost and comprises a series ofprojections 30 which extend from the planar first portion 14. Theprojections 30 are transverse to the lengthwise dimension of the belt 10and extend the entire width of the belt 10 perpendicularly to alongitudinal centerline.

With reference to FIG. 2, first portion 14 may also comprise areinforcing ply 32 coextensive with the underlying ply 18 and disposedalong an outer surface 34 thereof.

With continuing reference to FIG. 2, each of projections 30 comprise aninternal core 38 of energy-absorbing material which deflects relativelyeasily to a compression loading, yet is sufficiently resilient to returnto an initial configuration upon removal of compressive force. Theinternal core material is compressible and resilient when loaded withload approximately equal to a person's weight, i.e., the person for whomthe treadmill is intended. Suitable materials for use in the internalcore 38 are butyl, foam rubber, soft synthetic rubber. A preferredembodiment of the present invention utilizes polynorbornene as theinternal core material.

The projections 30 further comprise an overlying skin 42 ofabrasion-resistant, high friction material such as abrasion resistantsynthetic, natural rubber, blends. A preferred embodiment utilizesblends as the overlying skin 42.

With continuing reference to FIG. 2, an important aspect of the presentinvention is the initial, uncompressed configuration of the secondportion 28. Each projection is generally trapezoidal in cross sectionhaving a top 44, generally parallel to the first portion 14, and havingoppositely inclined side walls 46,47. Side walls 46,47 form opposite,equivalent angles +/−α with the centerline of the projection 30. Theprojections 30 are laterally spaced a distance D from centerline tocenterline so that, initially, the inclined side walls 46,47 of adjacentprojections 30 define V-shaped grooves 50 therebetween and the area ofcontact A1 between adjacent projections 30 is minimal. In the preferredembodiment, the projections 30 are 0.125-0.75 (height), α is between20-60 (degrees) and spaced from 0.25 to 1.0 (distance) apart.

When the upper belt section 12 is compressed, as for example by a user'sfoot, the projections 30 assume a secondary configuration as shown inFIG. 3. The side walls 46 are outwardly displaced because of thecompressible nature of the material used to form the internal core 38.The amount of compression can be varied due to factors such as internalcore material, lateral spacing of the projections, stiffness of theoverlying skin, and the profiles of the projections.

As is also illustrated in FIG. 3, upon downward compression of the upperbelt section 12, the tops 44 of the projections 30 remain essentiallyparallel to the first portion 14. The side walls 46,47 are displacedinto the initial V-shaped grooves 50 between adjacent projections 30 andthe area of contact A2 between adjacent projections 30 increases.

With reference again to FIG. 1, it is evident that the V-shaped grooves50 between adjacent projections 30 help the belt 10 ease around endrollers 52 as are normally present in exercising treadmills.

The preferred embodiments have been described, hereinabove. It will beapparent to those skilled in the art that the above methods mayincorporate changes and modifications without departing from the generalscope of this invention. It is intended to include all suchmodifications and alterations in so far as they come within the scope ofthe appended claims or the equivalents thereof.

Having thus described the invention, it is now claimed:
 1. An endlessbelt (10) having a width and a lengthwise dimension for use with anexercising treadmill including a planar first portion (14) comprising acontinuous underlying ply (18) of low friction material, the endlessbelt characterized by: a second portion (28) being disposed outwardly ofthe first portion, the second portion comprising a series of projections(30) extending the width of the belt, each projection having a pair ofoppositely inclined side walls (46, 47) and a top (44), the top beinggenerally parallel to the plane of the first portion, the tops ofadjacent projections being laterally spaced transversely to thelengthwise dimension so that adjacent projections have minimal areas ofcontact therebetween.
 2. The endless belt of claim 1 wherein each of theprojections comprise: an internal core (38) of material which iscompressible and resilient when loaded with a person's weight; and, anoverlying skin (42) of abrasion resistant material.
 3. The endless beltof claim 1 wherein the low friction material is selected from the groupconsisting of: UHMWE-PE, polyester, nylon.
 4. The endless belt of claim2 wherein the compressible and resilient material is selected from thegroup consisting of: butyl, polynorbornene, and foam rubber.
 5. Theendless belt of claim 2 wherein the abrasion resistant material isselected from the group consisting of: abrasion resistant synthetic,natural rubber, or blends thereof.
 6. The endless belt of claim 1wherein the first portion further comprises a reinforcing ply (32)disposed between the underlying ply and the second portion.
 7. Theendless belt of claim 2 wherein the contact areas of adjacentprojections is increased upon compression of the second portion.
 8. Anendless belt use in an exercising treadmill comprising: a continuousunderlying ply of low friction material; an internal core ofcompressible and resilient material disposed above the underlying ply,the internal core comprising a series of laterally spaced projectionsbeing transverse to the lengthwise dimension and extending the width ofthe belt; and, an overlying skin of abrasion resistant material, theoverlying skin being attached to the internal core.
 9. The endless beltof claim 1 wherein the pair of oppositely inclined side walls formopposite, equivalent angles +/−α with a centerline of the projectionwherein a is between 20° and 60°.